In-reservoir destruction of Blue-Green Algae and their toxins

人类目前面临的最大全球挑战之一是获得可靠、安全、清洁的饮用水。这在发展中国家尤为严重，因为在这些国家，人类活动往往对水质造成不利影响。虽然地球被称为蓝色星球，71%的表面被水覆盖，但几乎所有这些都是海水，不适合人类消费，也不适合用于工业和农业过程。地球上只有一小部分水是淡水(约3%)，其中只有不到1%可供使用，因为剩余的大部分都冻结在两极或冰川中。全球饮用水水库的水位和水质严重枯竭，联合国预测，到2025年，18亿人将遭受严重的经常性水资源短缺，三分之二的人口生活在缺水地区。在这些枯竭的水库中，来自农业、工业和生活垃圾的营养物质(硝酸盐和磷酸盐)水平很高，导致蓝藻大量繁殖，同时产生和释放危险的毒素。这些毒素可引起人类和动物的急性和慢性症状，导致健康不佳、死亡和癌症。当大量存在时，传统的水处理往往无法消除蓝绿藻细胞，导致人体暴露。此外，它们产生的毒素在处理过程中也非常稳定，使它们能够原封不动地进入饮用水。环境微生物学家琳达·劳顿教授和化学工程师彼得·罗伯逊教授率先提出了利用光和简单催化剂(TiO2光催化)来消除这些问题的创新水处理方法。我们已经成功地展示了快速有效地去除6类毒素中的4类(有证据表明，其余2类毒素--麻黄毒素和BNAA--将很容易被破坏，因为它们的化学结构更简单)。此外，我们亦已证明同样的处理方法对水中的有害微生物是有效的。我们已在实验室和试验范围内广泛评估这项令人振奋的技术，水务公司对全面实施这项技术十分感兴趣。一个限制因素是制定了一种简单的策略，在确保催化剂可以容易地移除的同时，暴露并照亮与水接触的催化剂。最有效的破坏是对纳米颗粒催化剂的破坏，这些催化剂不容易从水中去除。我们的目标是通过开发和测试令人振奋的新型光催化处理舱来改变处理水库蓝藻污染的方法，这些光催化处理舱由集成的浮动太阳能电池板持续供电，驱动低能量LED。约翰·欧文教授(圣安德鲁斯电化学家)将带来他在催化剂改性和表征以及电优化方面的世界领先专业知识。Christine Edwards博士(生物技术专家-RGU)和Lawton教授一起在氰基毒素的生产和检测领域处于领先地位，我们将与巴西的领先科学家合作，巴西的水库目前极度枯竭，遭受着显著的蓝绿藻水华及其相关毒素的折磨。这项合作将使我们能够在持续受到蓝藻污染的水体中测试我们的新型处理系统在水库内的部署，并在具有极好的太阳辐射的环境中推动极低的运行成本。在完成这项研究后，我们将推出完全可扩展的水库内水处理系统，该系统将可移植到任何发展中国家或发达国家，以消除有害的蓝藻水华、其他病原体和各种有毒污染物。

One of the greatest global challenges currently facing human-kind is access to reliable safe clean drinking water. This is particularly acute in developing countries where human activities often adversely impact water quality. While the earth is known as the blue planet with 71% of its surface covered in water, nearly all of this is seawater and not suitable for human consumption or is utilised in industrial and agricultural processes. Only a tiny proportion of the earth's water is freshwater (about 3%) and of this less than 1% is available for use, since much of the remainder is frozen at the poles or in glaciers. Water levels and quality in drinking water reservoirs across the globe are seriously depleted with the United Nation predicting that 1.8 billion people will suffer serious recurrent water shortages by 2025 and two thirds of the population living in areas of water stress.Of the water that remains in these depleted reservoirs, nutrient (nitrate and phosphate) levels from agriculture, industry and domestic waste are found to be high resulting in the mass growth of blue-green algal blooms along with the production and release of dangerous toxins. These toxins can cause acute and chronic symptoms in humans and animals resulting in ill-health, fatalities and cancers. When present in high numbers traditional water treatment often fails to eliminate the blue-green algal cells resulting in human exposure. Furthermore, the toxins they produce are also very stable during treatment allowing them to pass unaltered into drinking water. Innovative water treatment to eliminate these problems which uses light and a simple catalyst (TiO2 photocatalysis) has been pioneered by Professor Linda Lawton (Environmental Microbiologist - RGU) and Professor Peter Robertson (Chemical Engineer - QUB). We have successfully demonstrated the rapid and effective removal of 4 out of the 6 classes of toxins (evidence suggests the remaining 2 classes, saxitoxins & BNAA, will be easily destroyed as they are more simple chemical structures). Furthermore, we have also shown that the same treatment is effective against harmful microbes in water.We have extensively evaluated this exciting technology both in the laboratory and on a pilot scale with considerable interest from water utilities in seeing the full implementation within the provision of drinking water. One limiting factor has been developing a simple strategy to expose and illuminate catalyst in contact with water while ensuring that the catalyst can be readily removed. The most efficient destruction has been found for nano-particulate catalysts which cannot easily be removed from water. We aim to transform the approach to dealing with blue-green algal contamination of reservoirs by developing and testing exciting new photocatalytic treatment pods which are continually powered by integrated, floating solar panels which drive low energy LEDs. Professor John Irvine (Electrochemist - St Andrews) will bring his world leading expertise in catalyst modification and characterisation along with electro-optimisation. Dr Christine Edwards (Biotechnologist - RGU) along with Professor Lawton have led the field in the production and detection of cyanotoxins and we will collaborate with leading scientists in Brazil where reservoirs are currently extremely depleted and suffering from significant blue-green algal blooms and their associated toxins. This collaboration will allow us to test the in-reservoir deployment of our novel treatment system in water bodies which are consistently contaminated with blue-green algae and in an environment with excellent solar irradiation with which to drive the very low running cost treatment.On completion of this research we will launch a fully scalable in-reservoir water treatment system which will be transferable to any developing or developed country to eliminate hazardous blue-green algal blooms, other pathogens and a wide range of toxic pollutants.